The present application claims priority to French Application No. 01/05287 filed Apr. 19, 2001, the entire text of which is specifically incorporated by reference herein without disclaimer.
1. Field of the Invention
The invention relates to a method for the extraction and use of a glycoprotein fraction extracted from an archaebacterium: Halobacterium halobium. The product of the invention, when incorporated into a cosmetic preparation, indeed exhibits the characteristic feature of protecting the cells of the skin from the harmful effects of pollution and/or ultraviolet radiation.
2. Description of Related Art
Halobacteria are classified in the kingdom comprising archaebacteria, one of the three main branches of the phylogenetic tree. The other two are the eubacteria (also called prokaryotes) and the eukaryotes.
Archaebacteria have been identified in all the extreme niches at the frontiers of life: temperatures exceeding 100° C., acidity at pH=0 or salt concentrations which may exceed 30%.
Archaebacteria are equipped with atypical cell walls from which a component of the molecule of peptidoglycan, which is conventionally present in bacteria, muramic acid, is absent. Furthermore, while other organisms manufacture the lipids of their membrane by assembling two fatty acid chains with one molecule of glycerol via an ester bond, the lipids of archaebacteria are composed of long chains of isoprenyl alcohol which are attached to glycerol via ether bonds.
Halobacteria are extreme obligate bacteria. They indeed require, for their growth, very high salt concentrations (from 10 to 30%), KCl, MgCl2 and especially NaCl. These organisms have been isolated from natural media (Great Salt Lake in the USA or the Dead Sea in Israel) or artificial media (salterns). To maintain their internal osmotic pressure which should be in equilibrium with the NaCl concentration in the medium, halobacteria accumulate from 3 to 4 M of salt in their cytoplasm in the form of KCl. A suspension of halobacteria in a medium containing an NaCl concentration of 2 M causes complete loss of the stiffness of the bacterial envelope and the bacterium then assumes a round shape. Decreasing the salt concentration below 1 M leads to bacterial lysis.
Colonies of halobacteria are red in colour, their envelopes indeed contain coloured pigments (bacterio-ruberins) which protect them against intense ultraviolet radiation to which they are exposed.
Among halobacteria, Halobacterium halobium further possesses an additional outer envelope, the purple membrane, which serves as support for an original photosynthetic mechanism.
The conventional shape of Halobacterium in a salt-rich medium is that of an oblong bacillus 4 to 10 μm long and 0.7 μm in diameter. This bacterium possesses from 5 to 8 lophotrichous flagella. Halobacterium halobium is incapable of using carbohydrates as carbon and energy source.
The resistance capacity and the characteristic features of these bacteria make them very promising tools for industry. They are already being exploited in sectors as diverse as the agri-foodstuffs, paper, detergent or pharmaceutical industry.
American Patent Application U.S. Pat. No. 5,091,364 refers to the preparation of envelope glycoproteins extracted from cultures of archaebacteria with the aim, after enzymatic degradation of the glycoproteins, of using them to increase the immune defences of the body against infection.
Patent Application FR 2 590 273 also uses fractions derived from archaebacteria but in combination with synthetic sea water in the context of the manufacture of aesthetic products in dermatology.